组合跑道式养殖池系统设计及水力学特征

System design and hydraulic characterization of mixed-cell raceway-type pond system

为研究组合跑道式养殖池的工程设计参数和水力学特征,构建了一个跑道式养殖池试验模型。该模型由3个边长均为1.74 m的正方形单元池组成,池中间底部为集污孔;通过池壁设置的竖直进水管进水,在每个单元池中形成旋转水流。对单元池3个水深(距池底0.1 m,中间水深,水面下0.1 m)的水流进行流速测量,并考察对固体颗粒物的旋流集污效果。结果显示,当循环量从1 Q/h增加到1.5 Q/h时,池中水体的平均旋流速度从11.3 cm/s增加到15.6 cm/s,固体颗粒物去除率从44.5%增加到87.7%,占进水管出水孔出水速度的比值从6.3%增加到8.6%。研究表明,在1.5 Q/h循环量下,形成的旋转水流能有效地将沉积固体物旋流至中心排放口排出。

A prototype raceway was constructed to study system design parameters and hydraulic characterization of a mixed-cell raceway-type pond system. The raceway model consists of three square unit cell with each side length of 1. 74 m. The basic design concept of a mixed-cell raceway-type pond system was to operate the raceway as a series of square tanks,each having a center drain for continuous removal of settable solids and sludge. The pond was split into three 1. 74 m × 1. 74 m × 1. 50 m square units. The water inlet pipe was set along the vertical wall,so that a swirling flow in each unit cell was formed. The flow velocity in 3 kinds of water depth of the unit cell( 0. 1 m above the bottom,intermediate water depth,0. 1m beneath the water surface) were measured and the swirling effect of the solid particles were also investigated. Results showed that when circulation was increased from 1 Q / h to 1. 5 Q / h,the mean rotational velocity of pond water increased from 11. 3 cm / s to 15. 6 cm / s,and the removal rate of solid particles increased from 44. 5 % to87. 7 %. The ratio of rotational velocity in the pond by water velocity from the inlet also increased 6. 3 % to8. 6 %. In conclusion,at 1. 5 Q / h circulation flow rate,the formed rotational flow can effectively while the deposited solids to the central discharge outlet,which can provide the technical reference for the design of the mixed-cell raceway-type pond system.